The invention relates more particularly to a suspension thrust bearing device comprising an upper ring and a lower ring between which is arranged at least one row of rolling elements, for example, balls or rollers. The upper and lower rings are generally mounted in contact with lower and upper bearing or support parts, such as cups or caps. The upper and lower caps form a housing for the rings of the rolling bearing and provide the interface between the rings and the surrounding elements.
The suspension thrust bearing device is arranged in the upper part of the suspension strut between the body shell of the vehicle and a suspension spring. The spring is installed around a shock absorber piston rod of which the end is connected to the body shell of the vehicle via an elastic block which filters out vibrations. The suspension spring bears axially, directly or indirectly, on the lower bearing cap. The upper bearing cap for its part is fixed with respect to the body shell of the vehicle.
Such a suspension thrust bearing device makes it possible to transmit axial forces between the suspension spring and the body shell of the vehicle while allowing a rotational movement between the lower bearing cap and the filtering elastic block resulting from a turning of the steered wheels of the vehicle and/or from the compression of the suspension spring.
The patent application FR-A1-2 915 929 discloses a suspension thrust bearing provided with a lower support cap and with a rolling bearing mounted in contact against the latter. The support cap comprises a body made of rigid synthetic material onto which is overmoulded a filtration element forming a bearing surface for the suspension spring in order to absorb in part the vibrations generated by the latter. The filtration element also comprises a sealing lip which comes into frictional contact with an outer skirt of the upper bearing cap.
The suspension thrust bearing of this document does not make it possible to provide a good sealing of the rolling bearing. Specifically, on the inner side of the thrust bearing, a single narrow passage is provided between the upper bearing cap and the lower support cap to provide the sealing of the rolling bearing.
Therefore, under certain conditions, for example when the vehicle is driving along a flooded road or alternatively when the vehicle is being cleaned with a high-pressure jet of water, there may be some infiltration of water or other pollutant particles into the rolling bearing with detrimental effects on the life of the suspension thrust bearing.
The present invention aims to overcome this disadvantage.